Removable tower sleeve

ABSTRACT

A tower sleeve for sliding engagement with a tower that defines a tower longitudinal axis includes a main body that defines a body longitudinal axis and a channel longitudinally extending therethrough for slidably and selectively receiving at least part of a longitudinal section of the tower therein with the body axis generally parallel to the tower axis. A closing body connectable to said main body is movable between a first limit position and a second limit position relative to the main body. The closing body at least partially closes off the channel when in the first limit position so as to secure the sleeve in sliding engagement with the tower inside the channel, and opens up the channel when in the second limit position so as to allow the sleeve to engage and disengage from the tower in a direction generally transverse relative to the body axis.

CROSS-REFERENCE TO RELATED APPLICATION

[0001] This application is related to U.S. Provisional Application forPatent Serial No. 60/381,370 filed on May 20, 2002.

FIELD OF THE INVENTION

[0002] The present invention relates to raising platforms, and moreparticularly to a sleeve or platform that is removable from the tower itis mounted on for displacement there along.

BACKGROUND OF THE INVENTION

[0003] Raising platforms or sleeves are well known in the constructionart, as disclosed in U.S. Pat. No. 5,159,993 granted to St-Germain onNov. 3, 1992; U.S. Pat. No. 5,746,290 granted to St-Germain et al. onMay 5, 1998 or U.S. Pat. No. 6,311,800 granted to St-Germain et al. onNov. 6, 2001. Sleeves, including either a fixed (such as a freightelevator or the like) or a releasable platform, are usually available aspre-assembled onto a lower section of tower or mast along which they aredisplaced. Alternatively, the sleeves need to be slidably lowered ontothe lower section of the tower using a crane or the like.

[0004] Even though some pre-assembled sleeve/tower structures arerelatively small, some locations are either physically impossible toreach with a pre-assembled sleeve/tower structure or simply do not allowtheir assembly on site, depending on the presence of surroundingequipments or on the situation due to the construction stage reached atthat specific time.

[0005] Also, in case of failure of the raising mechanism or the likethat is usually attached to or mounted on the sleeve, one would need todisassemble to whole tower or scaffolding structure in order to removethe sleeve from the tower for its repair or replacement, which is reallytime consuming and generally expensive.

[0006] Accordingly, there is a need for an improved tower sleeve orraising platform.

SUMMARY OF THE INVENTION

[0007] It is therefore a general object of the present invention toprovide an improved tower sleeve.

[0008] An advantage of the present invention is that the tower sleeveobviates the above noted disadvantages.

[0009] Another advantage of the present invention is that the towersleeve is easily removable from the tower or mountable thereon, in adirection generally transverse relative to the longitudinal axis of thetower.

[0010] A further advantage of the present invention is that the towersleeve can be assembled onto or disassembled from the tower in arelatively small or restrained room size.

[0011] Yet another advantage of the present invention is that the towersleeve can be easily loaded and unloaded from conventionaltrucks/trailers using a conventional forklift or the like.

[0012] Still another advantage of the present invention is that thetower sleeve can be remotely operated from ground, especially during theself-erecting process.

[0013] Yet a further advantage of the present invention is that thetower sleeve can be removed from the tower that needs to remain on theconstruction site for supporting a tower crane at the top end thereof.

[0014] According to an aspect of the present invention, there isprovided a tower sleeve for sliding engagement with a tower, the towerdefining a tower longitudinal axis, the tower sleeve comprises: a mainbody, the main body defining a body longitudinal axis, the body defininga channel longitudinally extending therethrough for slidably andselectively receiving at least part of a longitudinal section of thetower therein with the body axis generally parallel to the tower axis; aclosing body connectable to the main body, the closing body beingmovable between a first limit position and a second limit positionrelative to the main body, the closing body at least partially closingoff the channel when in the first limit position so as to secure thetower sleeve in sliding engagement with the tower inside the channel,and opening up the channel when in the second limit position so as toallow the tower sleeve to engage and disengage from the tower in adirection generally transverse relative to the body axis.

[0015] In one embodiment, the main body defines generally opposed firstand second longitudinal body ends, the closing body being connectable tothe main body adjacent at least one of the first and second body endswhen in the first limit position.

[0016] In one embodiment, the channel defines generally opposed firstand second longitudinal open side edges on the main body, the closingbody including generally opposed first and second longitudinalcomponents, the first and second components being connectable to themain body adjacent the first and second open side edges, respectively.

[0017] In one embodiment, the channel has a generally V-shapedcross-section.

[0018] In one embodiment, the channel has a generally U-shapedcross-section.

[0019] Typically, the tower has a generally square-shaped cross-section,the channel having a generally square-shaped cross-section for slidablyand selectively receiving at least part of a longitudinal section of thetower therein.

[0020] In one embodiment, the closing body pivotally connects to themain body about a pivot axis generally parallel to the body axis, theclosing body being pivotable between the first and second limitpositions.

[0021] Typically, the closing body defines first and second bodysegments, the first body segment pivotally connecting to the main bodybetween the first and second limit positions, the second body segmentbeing for sliding engagement with the tower when the closing body is inthe first limit position.

[0022] Typically, the second body segment includes at least one lowfriction surface member mounted on the first body segment for slidingengagement with the tower when the closing body is in the first limitposition.

[0023] Alternatively, the second body segment includes a roller assemblymounted on the first body segment for rolling engagement with the towerwhen the closing body is in the first limit position.

[0024] Typically, the roller assembly includes a shaft and at least oneroller, the shaft having generally opposed first and second longitudinalshaft ends, the first shaft end connecting to the main body, the shaftsecond end rotatably supporting the at least one roller for rollingengagement with the tower when the closing body is in the first limitposition.

[0025] Alternatively, the second body segment includes at least oneroller rotatably mounted on the first body segment for rollingengagement with the tower when the closing body is in the first limitposition. The first body segment is a shaft, the shaft having generallyopposed first and second longitudinal shaft ends, the first shaft endreleasably connecting to the main body, the second shaft end rotatablysupporting the at least one roller.

[0026] In one embodiment, the closing body includes at least twocomponents, each of the at least two components being connectable to themain body independently from each other, each of the at least twocomponents being movable between the first and second limit positions,each of the at least two components at least partially closing off arespective section of the channel when in the first limit position.

[0027] In one embodiment, the tower further includes first and secondtower engaging bodies mounted on the main and closing bodiesrespectively for sliding engagement with the tower, the first towerengaging body extending inwardly from the main body into the channel,the second tower engaging body extending inwardly from the closing bodyinto the channel when the closing body is in the first limit position.

[0028] Typically, each of the first and second tower engaging bodiesincludes either a roller assembly for rolling engagement with the toweror a low friction surface member for sliding engagement with the tower.

[0029] In one embodiment, the main body includes at least one actuatorassembly for selectively securing and displacing the tower sleeve alongthe tower when the closing body is in the first limit position.

[0030] Typically, the at least one actuator assembly includes a pistonram mounted generally longitudinally on the main body and a piston headsupport, the piston ram defining generally opposed first and secondlongitudinal ram ends, the first ram end pivotally mounting on the mainbody, the second ram end pivotally mounting on the piston head support,the piston head support slidably securing to the main body.

[0031] Typically, the main body includes a head support guiding railmounted thereon, the head support guiding rail slidably supporting thepiston head support therein. The head support guiding rail includes alow friction surface member mounted thereon for sliding engagement withthe piston head support.

[0032] In one embodiment, the closing body includes a securing member,the securing member releasably connecting to the main body for securingthe closing body in the first limit position.

[0033] According to an aspect of the present invention, there isprovided a tower sleeve for sliding engagement with a tower, the towerdefining a tower axis and a tower longitudinal sidewall generallyparallel to the tower axis, the tower sleeve comprises: a sleevelongitudinal sidewall for selectively covering at least a longitudinalsection of the tower sidewall, the sleeve sidewall including a firstlongitudinal wall section and a second longitudinal wall section, thefirst and second longitudinal wall sections being generally transverselyadjacent to one another, the second wall section movably connecting tothe first wall section; the second wail section being movable between afirst limit position and a second limit position, the second wallsection being configured and sized so as to secure the tower sleeve insliding engagement with the tower when in the first limit position, andso as to allow the tower sleeve to engage and disengage from the towerin a direction generally transverse relative to the tower axis when inthe second limit position.

[0034] Other objects and advantages of the present invention will becomeapparent from a careful reading of the detailed description providedherein, with appropriate reference to the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Further aspects and advantages of the present invention willbecome better understood with reference to the description inassociation with the following Figures, in which like referencecharacters indicate like elements throughout, wherein:

[0036]FIG. 1 is a top perspective view of an embodiment of a towersleeve in accordance with the present invention, showing the towersleeve with a U-shaped channel mounted on a tower with a square-shapedcross-section;

[0037]FIG. 2 is a front perspective view of the embodiment of FIG. 1,showing the closing panels in the open limit position;

[0038]FIG. 3 is a side perspective view of the embodiment of FIG. 1,showing the closing panels in the closed limit position;

[0039]FIG. 4 is a top view of the embodiment of FIG. 1, showing theclosing panels in the closed limit position with the tower located intothe sleeve channel;

[0040]FIG. 5 is an exploded top view similar to FIG. 4, showing theclosing panels in the open limit position with the tower moved away fromthe sleeve channel;

[0041]FIG. 6 is an enlarged partially broken section view taken alongline 6 of FIG. 4, showing the tower sleeve mounted on a tower using lowfriction surface plates;

[0042]FIG. 7 is a schematic view similar to FIG. 6 of another embodimentof a tower sleeve in accordance with the present invention, showing atower sleeve with a V-shaped channel and roller assemblies for slidablysupporting a tower with a triangle-shaped cross-section; and

[0043]FIG. 8 is an enlarged partially broken section view taken alongline 8-8 of FIG. 3, showing the sliding engagement between the pistonhead support and the tower sleeve.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0044] With reference to the annexed drawings the preferred embodimentsof the present invention will be herein described for indicative purposeand by no means as of limitation.

[0045] Referring to FIGS. 1 and 2, there is shown an embodiment of atower sleeve 10 in accordance with the present invention for slidingengagement with a conventional tower 12, or mast used in scaffoldings orthe like, that defines a tower longitudinal axis 14. The tower sleeve10, guided for up-and-down movement along the tower 12 (see arrow A ofFIG. 1), is conventionally used to releasably and securely support aplatform (not shown) or the like on an interface plate structure 16, asshown in U.S. Pat. No. 5,159,993 granted to St-Germain on Nov. 3, 1992;U.S. Pat. No. 5,746,290 granted to St-Germain et al. on May 5, 1998 orU.S. Pat. No. 6,311,800 granted to St-Germain et al. on Nov. 6, 2001.One skilled in the art would understand that the tower sleeve 10 couldbe an integral part of a platform that moves up and down along the tower12 without departing from the scope of the present invention.

[0046] The sleeve 12 includes a main body 18 and a closing body 20connectable thereto. The main body 18 defines a body longitudinal axis22 and includes a channel 24 longitudinally extending therethrough forslidably and selectively receiving a longitudinal section of the tower12 therein, with the sleeve axis 22 generally parallel to the tower axis14. The sleeve 10 typically forms a sleeve longitudinal sidewall 11 thatselectively covers a longitudinal section of the tower 12. The sleevesidewall 11 includes first and second longitudinal wall sections thereofformed by the main body 18 and the closing body 20 respectively.

[0047] The closing body 20, or second wall section, is movable between afirst closed limit position and a second open limit position relative tothe main body 18, or first wall section. The closing body 20 at leastpartially closes off the channel 24 when in the first closed limitposition so as to secure the sleeve 10 in sliding engagement with thetower 12 inside the channel 24, as shown in FIGS. 1 3, and 4, and opensup the channel 24 when in the second open limit position, as shown inFIGS. 2 and 5, so as to allow the sleeve 10 to engage and disengage fromthe tower 12 in a direction generally transverse relative to the sleeveaxis 22, as indicated by arrow B in FIG. 5.

[0048] Typically, the channel 24, and the sleeve sidewall 11, have agenerally U-shaped cross-section. As shown in FIGS. 4 and 5, the towerhas a generally square-shaped cross-section and the channel 24 also hasa generally square-shaped cross-section for slidably and selectivelyreceiving a longitudinal section of the tower 12 therein.

[0049] The main body 18 defines generally opposed first and secondlongitudinal body ends 26, 28, and the closing body 20 is connectable tothe main body 18 adjacent at least one of the first and second body ends26, 28 when in the open position.

[0050] The channel 24 defines two generally opposed longitudinal openside edges 30 on the main body 18 extending between the first and secondbody ends 26, 28.

[0051] The closing body 20 includes two generally opposed components 32,preferably longitudinal, that are independently and releasablyconnectable to the main body 18 adjacent a respective one of the openside edges 30. Preferably, the closing body 20 defines a slit 33extending there along. The slit 33 allows for the sleeve 10 to clearsome wall anchors (not shown) retaining the tower 12 along a buildingstructure (not shown) during its up-and-down movement along the tower12, as illustrated in U.S. Pat. Nos. 5,159,993 and 5,259,479 granted toSt-Germain on Nov. 3, 1992 and Nov. 9, 1993, respectively. Typically,each longitudinal component 32 is pivotally connected to the main body18 about a pivot axis 34 generally parallel to the sleeve axis 22 so asto form door panels 36 pivotable between the open and closed limitpositions using conventional hinges 38 or the like, as indicated byarrow C of FIGS. 2 and 5, in a similar fashion than well known doubledoors or French doors. In order to releasably secure the panels 36 tothe main body 18 when in the closed limit position, a securing member,typically bolts 40 or the like fasteners are located along the panels36. Also, some locking mechanism (not shown) could be used for latchingthe panels 36 in their open limit position. Although not shown in theFigures, the closing body 20 could eventually be a single panel closingoff the entire channel opening and securing to both open side edges 30when in the closed limit position without departing from the scope ofthe present invention.

[0052] In order to ensure a proper sliding engagement between the sleeve10 and the tower 12 during the up-and-down displacement of the sleeve 10along the tower 12, the sleeve 10 includes first and second towerengaging bodies 42, 44 mounted on the main and closing bodies 18, 20respectively. The first tower engaging body 42 extends generallyinwardly from the main body 18 into the channel 24, and the second towerengaging body 44 extends generally inwardly from the closing body 20into the channel 24 when the closing body 20 is in the closed limitposition.

[0053] As shown in FIGS. 1 to 6, each first and second tower engagingbodies 42, 44 includes at least one low friction surface member 46,including conventional guiding bushings mode out of plastic-typematerials such as Teflon T™ or the like, for the sliding, and abutting,engagement with the tower 12, preferably at the corners thereof.

[0054] Referring more specifically to FIGS. 4 to 6, the closing body 20,or each panel 36 thereof, defines first and second panel segments 48, 50connected to each other. Alternatively, the first and second panelsegments 48, 50 are integral with each other. The first panel segment 48pivotally connects to the main body 18 between the closed and open limitpositions while the second panel segment 50 is for sliding engagementwith the tower 12 when the panel 36 is in the closed limit position.

[0055] Typically, the second panel segment 50 includes at least one lowfriction surface member 46 of the second tower engaging body 44 securedto the first panel segment 48 for sliding, and abutting, engagement withthe tower 12 when the panel 36 is in the closed limit position.

[0056] Now referring more specifically to FIG. 7, there is shown anotherembodiment of a tower sleeve 10′ in accordance with the presentinvention for sliding engagement with a conventional tower 12′ having agenerally triangle-shaped cross-section. Accordingly, the channel 24′,and the sleeve sidewall 11′, have a generally V-shaped cross-section forslidably and selectively receiving a longitudinal section of the tower12′ therein.

[0057] In this embodiment 10′, the first second tower engaging bodies42, 44 are roller assemblies 52 rotatably mounted on the main andclosing bodies 18′, 20′, respectively, for rolling, and abutting,engagement with the tower 12′ when the closing body 20′ is in the closedlimit position; which is sufficient for relatively low load capacityrated sleeve 10 with platform.

[0058] Accordingly, the first body segment 48′ of each closing bodycomponent 32 is a roller assembly 52. The roller assembly 52 has a shaft54 defining generally opposed first and second longitudinal shaft ends56, 58. The first shaft end 56 releasably connects to the main body 18′and the second shaft end rotatably supports, typically usingconventional roller bearings (not shown) or the like, at least oneroller 60 thereon, the latter being in rolling engagement with the tower12′ when the component 32 is in the closed limit position. The roller 60forms the second body segment 50′.

[0059] Obviously, although the second tower engaging body 44 includesroller assemblies 52, the first tower engaging body 42 could remain withlow friction surface member 46, or vice and versa, without departingfrom the scope of the present invention.

[0060] Referring back to FIGS. 1 to 3, the main body 18 of sleeve 10includes at least one, typically two generally opposed actuatorassemblies 62 for selectively securing and actuating displacement thesleeve 10 along the tower 12 when the closing body 20 is in the closedlimit position. Each actuator assembly 62 includes a piston ram 64,preferably a double-acting hydraulic ram, mounted generallylongitudinally on the main body 18 and a piston head support 66. Thepiston ram 64 defines generally opposed first and second longitudinalram ends 68, 70. The first ram end 68, or cylinder, pivotally mounts onthe main body 18, preferably at the second body end 28 and the secondram end 70, or piston rod, pivotally mounts on the piston head support66, the latter slidably securing to the main body 18.

[0061] The main body 18 includes a head support guiding rail 72 mountedthereon to slidably support the piston head support 66 therein. The headsupport guiding rail 72 includes a low friction surface member 74,including conventional guiding bushings mode out of plastic-typematerials such as Teflon TM or the like, mounted thereon for slidingengagement with the piston head support 66, as shown in FIG. 8.

[0062] Each second ram end 70 is provided with a hook 76 pivotallymounted thereon. The hooks 76 successively engage, and disengage,generally horizontally oriented rungs 78 of the tower 12. The rungs 78are substantially equally spaced apart along the tower 12. Each hook 76pivots between a hooking position in which the hook 76 engages a rung 78of the tower 12 and an unhooking position in which the hook 76 cannotengage the rungs 78. A hook biasing means (not shown) biases the hook 76in its hooking position. In the upward movement of the sleeve 10, thetop end surface of the hook 76 abuts the next higher rung 78 and forcesthe hook 76 to momentarily pivot in the unhooking position while passingat the rung level. In the downward movement of the sleeve 10, aconventional operator-activated unhooking means (not shown) formaintaining the hook 76 in the unhooking position is activated by anoperator (not shown) to allow the hook 76 to clear the rungs 78 whilepassing at the rung level, as explained in further details in U.S. Pat.No. 5,746,290 granted to St-Germain et al. on May 5, 1998. Obviously,different types of actuator mechanism could be used without departingfrom the scope of the present invention.

[0063] At least one well known conventional safety/emergency brakingsystem 80 is mounted on the main body 18 to prevent any accidentaldownward movement of the sleeve 10 along the tower 12; such typicalsafety/emergency braking system 80 are illustrated in U.S. Pat. No.5,159,993 granted to St-Germain on Nov. 3, 1992; U.S. Pat. No. 5,746,290granted to St-Germain et al. on May 5, 1998 or U.S. Pat. No. 6,311,800granted to St-Germain et al. on Nov. 6, 2001.

[0064] Preferably, the sleeve 22 carries its own power system unit 82 toactivate the hydraulic rams 64.

[0065] Although the embodiments shown and described hereinabove havetheir channel 24 substantially entirely receiving a section of the tower12 therein with the closing body 20 being substantially a door or thelike to close off the channel 24, one skilled in the art wouldunderstand that the channel 24 could receive only a portion (such as afirst half) of such a section of the tower with the closing body 20covering the remaining portion of the tower section (the other half)without departing from the scope of the present invention.

[0066] Although the present tower sleeve has been described with acertain degree of particularity it is to be understood that thedisclosure has been made by way of example only and that the presentinvention is not limited to the features of the embodiments describedand illustrated herein, but includes all variations and modificationswithin the scope and spirit of the invention as hereinafter claimed.

I claim:
 1. A tower sleeve for sliding engagement with a tower, saidtower defining a tower longitudinal axis, said tower sleeve comprising:a main body, said main body defining a body longitudinal axis, said bodydefining a channel longitudinally extending therethrough for slidablyand selectively receiving at least part of a longitudinal section of thetower therein with said body axis generally parallel to the tower axis;a closing body connectable to said main body, said closing body beingmovable between a first limit position and a second limit positionrelative to said main body, said closing body at least partially closingoff said channel when in said first limit position so as to secure saidtower sleeve in sliding engagement with the tower inside said channel,and opening up said channel when in said second limit position so as toallow said tower sleeve to engage and disengage from the tower in adirection generally transverse relative to said body axis.
 2. The sleeveof claim 1, wherein said main body defines generally opposed first andsecond longitudinal body ends, said closing body being connectable tosaid main body adjacent at least one of said first and second body endswhen in said first limit position.
 3. The sleeve of claim 1, whereinsaid closing body pivotally connects to said main body about a pivotaxis generally parallel to said body axis, said closing body beingpivotable between said first and second limit positions.
 4. The sleeveof claim 1, wherein said channel defines generally opposed first andsecond longitudinal open side edges on said main body, said closing bodyincluding generally opposed first and second longitudinal components,said first and second components being connectable to said main bodyadjacent said first and second open side edges, respectively.
 5. Thesleeve of claim 1, wherein said channel has a generally V-shapedcross-section.
 6. The sleeve of claim 1, wherein said channel has agenerally U-shaped cross-section.
 7. The sleeve of claim 6, wherein thetower has a generally square-shaped cross-section, said channel having agenerally square-shaped cross-section for slidably and selectivelyreceiving at least part of a longitudinal section of the tower therein.8. The sleeve of claim 3, wherein said closing body defines first andsecond body segments, said first body segment pivotally connecting tosaid main body between said first and second limit positions, saidsecond body segment being for sliding engagement with the tower whensaid closing body is in said first limit position.
 9. The sleeve ofclaim 8, wherein said second body segment includes at least one lowfriction surface member mounted on said first body segment for slidingengagement with the tower when said closing body is in said first limitposition.
 10. The sleeve of claim 8, wherein said second body segmentincludes a roller assembly mounted on said first body segment forrolling engagement with the tower when said closing body is in saidfirst limit position.
 11. The sleeve of claim 10, wherein said rollerassembly includes a shaft and at least one roller, said shaft havinggenerally opposed first and second longitudinal shaft ends, said firstshaft end connecting to said main body, said shaft second end rotatablysupporting said at least one roller for rolling engagement with thetower when said closing body is in said first limit position.
 12. Thesleeve of claim 1, wherein said closing body defines first and secondbody segments, said first body segment releasably connecting to saidmain body, said second body segment being for sliding engagement withthe tower when said closing body is in said first limit position. 13.The sleeve of claim 12, wherein said second body segment includes atleast one roller rotatably mounted on said first body segment forrolling engagement with the tower when said closing body is in saidfirst limit position.
 14. The sleeve of claim 13, wherein said firstbody segment is a shaft, said shaft having generally opposed first andsecond longitudinal shaft ends, said first shaft end releasablyconnecting to said main body, said second shaft end rotatably supportingsaid at least one roller.
 15. The sleeve of claim 12, wherein saidsecond body segment includes at least one low friction surface membermounted on said first body segment for sliding engagement with the towerwhen said closing body is in said first limit position.
 16. The sleeveof claim 1, wherein said closing body includes at least two components,each of said at least two components being connectable to said main bodyindependently from each other, each of said at least two componentsbeing movable between said first and second limit positions, each ofsaid at least two components at least partially closing off a respectivesection of said channel when in said first limit position.
 17. Thesleeve of claim 1, further including first and second tower engagingbodies mounted on said main and closing bodies respectively for slidingengagement with the tower, said first tower engaging body extendinginwardly from said main body into said channel, said second towerengaging body extending inwardly from said closing body into saidchannel when said closing body is in said first limit position.
 18. Thesleeve of claim 17, wherein each of said first and second tower engagingbodies includes a roller assembly for rolling engagement with the tower.19. The sleeve of claim 17, wherein each of said first and second towerengaging bodies includes a low friction surface member for slidingengagement with the tower.
 20. The sleeve of claim 1, wherein said mainbody includes at least one actuator assembly for selectively securingand displacing said tower sleeve along the tower when said closing bodyis in said first limit position.
 21. The sleeve of claim 20, whereinsaid at least one actuator assembly includes a piston ram mountedgenerally longitudinally on said main body and a piston head support,said piston ram defining generally opposed first and second longitudinalram ends, said first ram end pivotally mounting on said main body, saidsecond ram end pivotally mounting on said piston head support, saidpiston head support slidably securing to said main body.
 22. The sleeveof claim 21, wherein said main body includes a head support guiding railmounted thereon, said head support guiding rail slidably supporting saidpiston head support therein.
 23. The sleeve of claim 22, wherein saidhead support guiding rail includes a low friction surface member mountedthereon for sliding engagement with said piston head support.
 24. Thesleeve of claim 1, wherein said closing body includes a securing member,said securing member releasably connecting to said main body forsecuring said closing body in said first limit position.
 25. A towersleeve for sliding engagement with a tower, said tower defining a toweraxis and a tower longitudinal sidewall generally parallel to the toweraxis, said tower sleeve comprising: a sleeve longitudinal sidewall forselectively covering at least a longitudinal section of the towersidewall, said sleeve sidewall including a first longitudinal wallsection and a second longitudinal wall section, said first and secondlongitudinal wall sections being generally transversely adjacent to oneanother, said second wall section movably connecting to said first wallsection; said second wall section being movable between a first limitposition and a second limit position, said second wall section beingconfigured and sized so as to secure said tower sleeve in slidingengagement with the tower when in said first limit position, and so asto allow said tower sleeve to engage and disengage from the tower in adirection generally transverse relative to the tower axis when in saidsecond limit position.